Coming soon to a forest/lake/sea near you: Invasive species

Almost 20 years ago folks in Brazil thought imported giant African land snail would make a fine food delicacy — maybe with the plug “If you like escargot, you’ll love giant African land snail.”

In Washington in the 1930s, the marketing campaign that may have welcomed ravenous rat-like nutria, native of South America, could have been along the lines of, “Here, honey, let’s bundle you up in this lovely swamp-rat wrap.”

Ivy kills trees

However they arrived, these and countless other invasive, exotic, non-native species have caused mayhem when plunked into new environments. This story by Mac Margolis in Newsweek International from the Jan. 15 issue has a great global look at the topic.

Margolis references Cornell University’s David Pimentel, a leading scholar on the subject, who says that in the United States, as much as 40 percent of all extinctions can be blamed on invasive weeds, predators or pathogens.

Also from the story, this amusingly-written overview:

Scores of bioinvaders are deliberately set loose by farmers or eggheads trying to outsmart nature (importing snakes to chase rats), gardeners with exotic tastes (knotweed) or entrepreneurs too clever by half (seeking the perfect escargot). Bioinvaders are also ferocious competitors; free from the predators of their homelands, they prosper on virgin territory, monopolizing food supply and reproducing at a rate that would make rabbits blanch. Once lodged in a new land, the intruding species may never go away, forcing public authorities to battle them again and again with earthmoving equipment, fire and poison–a job as futile as Sisyphus’.

And the Northwest has more than nutria to contend with (see this link for info on Lake Washington nutria research). Divers with the Washington Scuba Alliance have been battling slimy fields of invasive tunicates. Volunteers in Seattle parks are warring against strangling vines of ivy — which might make one question the wisdom of allowing nurseries and others to continue selling the pesky weed.